| Objective:To explore the effects of different occlusal contact on the preservation of bone tissue around the implant and the occlusal state,and to provide a theoretical basis for the occlusal adjustment of clinical implant restoration.Methods:From December 2016 to February 2018,30 patients who received single posterior tooth implantation treatment in the stomatological hospital of Jilin university met the inclusion criteria.The patients were randomly divided into three groups according to the degree of occlusal tightness of the prosthesis and the paired jaw teeth according to the standardized implantation process,and were recorded as group a,group b and group c,respectively.Group a:the articulating paper of 12?m cannot be extracted from the prosthesis and the paired jaw teeth when the teeth were clenched;Group b:when the teeth were clenched:20?m articulating paper could be extracted from the prosthesis and the paired jaw teeth with resistance;Group c:the 40 u m articulating paper could be extracted between the prosthesis and the paired jaw teeth.On the day of restoration,3 months after restoration,6 months after restoration,and 12 months after restoration,dental fi lm s were taken to measure the changes in bone height around the implant.Application of digital occlusal sensor(Tekscan ?)was done to measure the ratio of the bite force of the prosthesis and the occlusal balance.The measurement time was the day of restoration,3 months,6 months and 12 months after restoration.The satisfaction of patients was investigated by visual analogue scoring.Results:1.The mesial bone tissue changes in the three groups a,b and c at 3 months after functional load were 0.00±0.24mm,-0.27±0.24mm and 0.01±0.33mm.The changes of distal bone tissue Were:0.02±0.17mm,-0.1±0.28mm and-0.0±0.14mm.There was no significant difference between the three groups(p>0.05).2.The mesial bone tissue changes of the implant groups a,b and c at 6 months after functional load were:-0.05±0.29mm,-0.22±0.38mm,and 0.05 ±0.32mm.The changes of distal bone tissue were 0.12±0.34mm,-0.16±0.42mm and 0.00 ± 0.26mm.There was no significant difference between the three groups(p>0.05).3.The mesial bone tissue changes of the implant groups a,b and c at 12 months after functional load were-0.12±0.27mm,-0.31±0.42mm and-0.01 ±0.30mm.The changes of distal bone tissue were:0.07±0.36mm,-0.21 ±0.45mm,-0.08±0.29mm.There was no significant difference between the three groups(p>0.05).4.Occlusal balance indexes of group a,b and c before restoration were-0.39±0.14,-0.38±0.25 and,0.37±0.15.The occlusal balance indexes on the day of restoration were-0.27±0.15,-0±0.25and-0.30±0.14.The occlusal balance indexes were-0.05±0.05,-0.15±0.15 and-0.19±0.17 at 3 months of restoration.The occlusal balance indexes were-0.03±0.03,-0.06±0.12 and-0.10±0.10 at the 6th month of restoration.The occlusal balance indexes were-0.00±0.02,-0.03±0.08 and-0.09±0.06 at 12 months of restoration.Among them,the occlusal balance index of group a was significantly different from that of group a at 3-6 months and 6-12 month s after restoration(p<0.05).The occlusal balance index of group b and group c was not significantly increased within 3 months after the restoration,which was significantly different from that of group a(p<0.05).The occlusal balance index of group a and group c was significantly different at 12 months after restoration(p<0.05).5.The occlusal force of the prostheses of group a,b and c at 3 months after functional load was 14.83%±2.52%,11.39%±4.19%and 9.38%±2.94%.The occlusal force of group a was relatively large,with a statistical difference between group b and c(p<0.05).The occlusal force at 6 months after functional load was 16.32%±2.27%,15.63%±5.97%and 10.88%±3.03%.The occlusal force at 12 months after functional load was 18.11%±2.03%,17.6%±3.34%and 12.88%±2.66%.At 6 and 12 months after restoration,the occlusal force undertaken by the prosthesis in group a and group b was statistically different from that in group c(p<0.05).6.The comparison of the occlusal force between the prostheses and the same name on the opposite side of group a,b and c at 3 months after the functional load were 0.98,0.61 and 0.54,there was a statistical difference between group a and group b,and between group a and group c(p<0.05).The comparison of the occlusal force between the prostheses and the same name on the opposite side of group a,b and c at 6 months after the functional load were 1.01,0.87 and 0.66.There was a statistical difference between group a and group c(p<0.05).The comparison of the occlusal force between the prostheses and the same name on the opposite side of group a,b and c at 3 months after the functional load were 1.01,0.92 and 0.80.There was a statistical difference between group a and group c(p<0.05).7.The success rate of implants in all three groups was 100%.8.Patients in the group a and group b were 100%satisfied,and patients in the group c was 95%satisfied.Conclusions:1.The prostheses with occlusal contact of 12 ?m,20 ?m and 40 ?m stabilized the bone tissue around the implant after 1 year of functional load without obvious bone resorption.2.The degree of occlusal contact has a significant impact on the occlusal force undertaken by the implant prosthesis when it is performing its functions.When the contact is tightness,it can quickly restore the bite force similar to that of the opposite teeth.3.Occlusal contact tightness has a significant impact on the state of occlusal balance,and the speed of restoring occlusal balance and the degree of final balance are positively correlated with the degree of occlusal contact tightness.4.12?m occlusal contact can restore occlusal balance more quickly after restoration,and undertake greater bite force,maintain the stability of bone tissue around the implant. |
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